Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a first image of a display screen or portion thereof withtransitional graphical user interface showing our new design;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof;

FIG. 5 is a fifth image thereof;

FIG. 6 is a sixth image thereof; and,

FIG. 7 is a seventh image thereof.

The outer perimeter shown in a pair of dashed broken lines in thedrawings represents a display screen or portion thereof and forms nopart of the claimed design. The remaining dashed broken lines in thedrawings illustrate portions of the transitional graphical userinterface that form no part of the claimed design.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1 through 7. The process or period inwhich one image transitions to another image forms no part of theclaimed design.

CLAIM We claim the ornamental design for a display screen or portionthereof with transitional graphical user interface, as shown anddescribed.